For the first time in Marine Corps history, a group of 40 female Marines will begin a fully integrated combat training course alongside male students at Marine Corps Base Camp Pendleton in California.

The females Marines arrived Tuesday for the 29-day Marine Combat Training, previously only open to males on the West Coast, and be integrated at the platoon and squad level, Capt. Joshua Pena told the San Diego Union-Tribune.

Women previously trained on the East Coast at Camp Lejeune in North Carolina, but a new Marine Corps policy decided all recruits from states west of the Mississippi River would train at Camp Pendleton.

“This initiative is part of a Marine Corps effort to enhance the entry-level training program for all Marines and to better reflect how the Marine Corps is structured in the operating forces,” Pena said. The Marine Corps started planning for female Marines about a year ago, modifying housing, medical services, and bathrooms, Pena told the Orange County Register . Ultimately, roughly 1,700 women will train at the base and they will be held to the same standards.